

A289972


Number of sets S (cubic acute nset), with cardinality A089676(n) >= 3, of points in {0,1}^n in real ndimensional Euclidean space such that every angle determined by three distinct points in S is acute.


2




OFFSET

1,3


COMMENTS

Consider the 2^n points {0,1}^n in real Euclidean space. Then A089676(n) = maximal size of a subset S of these 2^n points such that there is no triple of points P,Q,R in S which subtends a right angle. That is, we are not allowed to have PQ perpendicular to RQ. Here we count the number of such sets.


LINKS

Table of n, a(n) for n=1..8.
D. Bevan, Sets of Points Determining Only Acute Angles and Some Related Coloring Problems, Electronic J. of Combinatorics, 13(1), 2006, #R12.
Fausto A. C. Cariboni, Complete solutions for a(3)a(6)
Fausto A. C. Cariboni, Complete solutions for a(7)


CROSSREFS

Cf. A089676.
Sequence in context: A012610 A012721 A297095 * A179472 A009341 A015201
Adjacent sequences: A289969 A289970 A289971 * A289973 A289974 A289975


KEYWORD

nonn,hard,more


AUTHOR

Fausto A. C. Cariboni, Jul 16 2017


STATUS

approved



